Foe in eastern state holding me back (5)
I believe the answer is:
enemy
'foe' is the definition.
(I know that foe can be written as enemy)
'eastern state holding me back' is the wordplay.
'eastern' becomes 'e'.
'state' becomes 'ny' (abbreviation for New York the US state).
'holding' means one lot of letters goes inside another.
'back' shows that the letters should be reversed in order.
'me' in reverse letter order is 'em'.
'ny' enclosing 'em' is 'nemy'.
'e'+'nemy'='ENEMY'
'in' is the link.
(Other definitions for enemy that I've seen before include "Division" , "Yemen (anag.)" , "Hostile person, foe" , "Hostile opponent" , "Armed adversary" .)